How does a Declare Expression update property values in Pega?

A Declare Expression is a specialized rule in Pega that allows for the automatic calculation and updating of a property value based on specified conditions or expressions defined by the user. When certain conditions are met or when the values of referenced properties change, the framework automatically evaluates the Declare Expression, recalibrating the property it is linked to without requiring manual intervention or direct triggering by user actions.

This functionality allows for data consistency and real-time updates, ensuring that the system accurately reflects the most current data without necessitating explicit processes for updates. This is particularly valuable in scenarios where dynamic calculations or conditional data presentations are required as part of the business logic.

Other options suggest mechanisms such as user-triggered events, external API calls, or form submissions, which do not inherently align with the automated nature of Declare Expressions. The core strength of Declare Expressions lies in their ability to operate independently in response to changing data conditions, making them highly effective for creating reactive and intelligent applications in Pega.